Many exercise bicycles (also known as static bicycles) provide only for exercising the legs by operating pedals against an adjustable resistance. Some such machines, however, are also provided with means for exercising the arms and upper part of the body. This movement is achieved by making the handle-bars perform a reciprocatory movement which, in practice, is directly driven from the motion of the pedals.
In known such machines an eccentric mechanism is provided, which is connected to the pedals and is connectable, by means of a pin or similar element, to the lower end of the handle-bar support column in such a way as to cause a reciprocating motion of the handle-bars to take place in synchronism with the rotation of the pedals.
If the utiliser does not wish to perform the exercises involved with the upper limbs and the trunk it is possible to disconnect the reciprocating motion drive to leave the handle-bars in a fixed position: this is achieved by uncoupling the eccentric connection, for example by extraction of the pin which makes the connection. This conversion from one type of operation to the other is not, however, very easy to achieve and requires an operation, which whilst being simple, is rather inconvenient and is thus not always voluntarily effected by the utiliser. Such an exercise bicycle is for example known from the Swiss Pat. No. 453,982 in the name of the same Applicant which is herein incorporated by reference.